Calculate allele frequencies and test for Hardy-Weinberg equilibrium instantly. A free, precise online genetics tool for students and researchers.
AI Generation Prompt
Hardy-Weinberg Equilibrium & Allele Frequency Calculator Specification
Overview
This single-file web application serves as an interactive laboratory companion for students and researchers. It enables the immediate computation of allele frequencies, expected genotype frequencies, and population equilibrium status (Chi-square test) based on raw phenotypic or genotypic data.
Core Technical Constraints
- Architecture: Single HTML file containing embedded CSS and Vanilla JavaScript.
- State Management: Zero persistence. Use in-memory variables only. No localStorage, sessionStorage, or IndexedDB.
- Environment: Compatible with null-origin iframe sandboxing. No external tracking scripts or cookies.
- Interaction: No
alert(),prompt(), orconfirm(). Use custom modal components if user interaction is required.
UI/UX Design
Layout
- Header: Simple, clean title with a brief explanation subtitle.
- Main Input Panel: A clean form area featuring input fields for:
- Count of Homozygous Dominant (AA)
- Count of Heterozygous (Aa)
- Count of Homozygous Recessive (aa)
- Calculation Engine: Automatically updates results in real-time as the user types (oninput events), eliminating the need for a 'Calculate' button.
- Results Dashboard: A grid-based display showing:
- Allele frequencies (p, q).
- Expected Genotype counts and frequencies.
- Chi-square statistic and status indicator (e.g., "In Equilibrium" vs "Deviation Detected").
- Visual Component: A simple, lightweight chart (using CSS-based bars or a lightweight SVG library) visualizing the difference between Observed and Expected distributions.
Aesthetic & Visuals
- Palette: Use a professional, high-contrast light theme.
- Background:
#f8fafc(Cool Gray 50) - Primary Brand/Action Color:
#2563eb(Blue 600) - Success (Equilibrium):
#16a34a(Green 600) - Warning (Deviation):
#dc2626(Red 600) - Text:
#1f2937(Gray 800)
- Background:
- Typography: Sans-serif, system-ui font stack for fast loading and readability.
- Animations: Subtle
transitionproperties on input focus states and result cards. Use CSS-only fading for updating statistical figures.
Feature Requirements
- Dynamic Form: Validate inputs in real-time (ensure numbers are non-negative and integers).
- Chi-Square Analysis: Automatically compute the Chi-square value using 1 degree of freedom.
- Result Interpretation: Provide a plain-language explanation of the Chi-square results.
- Responsive Strategy:
- Mobile: Stack inputs and results vertically.
- Desktop: Side-by-side layout (Inputs on left, Results on right).
- Accessibility: Ensure all inputs have proper labels, and error messages (for invalid inputs) are clearly visible using screen-reader-friendly ARIA live regions.
- Export: Include a "Print Results" button that uses
window.print()to generate a clean, printer-friendly summary of the current session data.
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Files being used
Frequently Asked Questions
Everything you need to know about using this application.
What is the Hardy-Weinberg Equilibrium?
The Hardy-Weinberg Equilibrium is a fundamental principle in population genetics stating that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences. It relies on a mathematical model where p represents the frequency of the dominant allele and q represents the frequency of the recessive allele, satisfying the equation p² + 2pq + q² = 1. Our tool helps calculate these variables based on your input data.
How does this calculator determine if a population is in equilibrium?
This calculator performs a Chi-square goodness-of-fit test by comparing your observed genotype counts against the expected counts derived from the Hardy-Weinberg equation. By calculating the difference between these sets, it determines if the deviation is statistically significant or due to chance. If the calculated Chi-square value is below the critical threshold, the population is generally considered to be in Hardy-Weinberg equilibrium. If it exceeds the threshold, it suggests that evolutionary forces like mutation, selection, or migration may be occurring.
Can I use this tool for academic research?
Yes, this tool is designed for educational purposes and quick data verification. It provides precise calculations for allele frequencies (p and q) and expected genotype frequencies (homozygous dominant, heterozygous, and homozygous recessive). While excellent for homework, lab reports, and introductory research, always double-check complex statistical analyses with professional-grade bioinformatics software for publication-level requirements. This tool is a client-side calculator and does not save any data.
Is any data saved when I use this calculator?
No, your data is never saved, transmitted, or stored. This application functions entirely within your browser's memory using client-side JavaScript, meaning it is completely private and secure for any sensitive genetic data you might input. Since this application does not use cookies, localStorage, or server-side databases, your privacy is protected by design. Once you close the browser tab, all input and calculation data are permanently cleared from the session.
